Interested on mining on this $20 computer that only draws 250mA, runs OpenWrt. It has ETHERNET, WIFI, USB, UART, 20+ GPIOs but size is only one square inch...? 
https://www.hackster.io/vocore
CPU mining in this level is not profitable... if you have free electricity you probably won't get your hardware cost back in some years https://www.hackster.io/vocore